[Bug libstdc++/118681] [C++17] unsynchronized_pool_resource may fail to respect alignment

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118681

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Although this means we'll never use some pool sizes. For allocate(48, 8) it
would be fine to use the 48-byte pool but max(bit_ceil(48), 8) would mean we
use the 64-byte pool instead.